Electrochromic properties of nanochromic windows assembled by the layer-by-layer self-assembly technique

Nanostructure controlled electrochromic (EC) multilayer films were assembled by the layer-by-layer (LBL) technique using poly(aniline-N-butylsulfonate)s (PANBUS) as polyanion, and vinyl benzyl dimethyl alkyl ammonium-chloride (VBDA) and polyaniline as the counter cation. The building up of such multilayer films on an indium-tin oxide (ITO) substrate was characterized by the increment of the absorbance through UV–Vis spectroscopy and layer thickness. Electrochromic response was highly dependent on the alkylchain length of VBDA. Higher color contrast was observed when the EC film was prepared from the VBDA having a shorter alkylchain length. An all-solid-state EC display showed EC response at 3 V within 5 s with a stable memory effect.